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Is there a way to convert a string to an enum?
enum eCommand{fred, joe, harry}
eCommand theCommand= cast(eCommand, 'joe');??
I think I just have to search for the enum (eg loop).
cheers
Steve
252
IsDefined() method to check if a given string name or integer value is defined in a specified enumeration. Thus, the conversion of String to Enum can be implemented using the Enum. Parse ( ) and Enum.
We've made a number of convenience additions to the enum APIs in the dart:core library (language issue #1511). You can now get the String value for each enum value using . name: enum MyEnum { one, two, three } void main() { print(MyEnum.one.name); // Prints "one". }
The Java enum type provides a language-supported way to create and use constant values. By defining a finite set of values, the enum is more type safe than constant literal variables like String or int.
To convert a string to ENUM or int to ENUM constant we need to use Enum. Parse function. Here is a youtube video https://www.youtube.com/watch?v=4nhx4VwdRDk which actually demonstrate's with string and the same applies for int.
Dart 2.6 introduces methods on enum types. It's much better to call a getter on the Topic or String itself to get the corresponding conversion via a named extension. I prefer this technique because I don't need to import a new package, saving memory and solving the problem with OOP.
I also get a compiler warning when I update the enum with more cases when I don't use default, since I am not handling the switch exhaustively.
Here's an example of that:
enum Topic { none, computing, general }
extension TopicString on String {
Topic get topic {
switch (this) {
case 'computing':
return Topic.computing;
case 'general':
return Topic.general;
case 'none':
return Topic.none;
}
}
}
extension TopicExtension on Topic {
String get string {
switch (this) {
case Topic.computing:
return 'computing';
case Topic.general:
return 'general';
case Topic.none:
return 'none';
}
}
}
This is really easy to use and understand, since I don't create any extra classes for conversion:
var topic = Topic.none;
final string = topic.string;
topic = string.topic;
(-:
147
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